They still mean something in serious discussions. If you find that media use seems to dilute the meaning of a term so as to be uselessly vague, consider the likelihood that it is intentional. (Very high, IMO.) The critical-thinking-not-allowed topics are especially interesting to pay attention to: who is served by devaluing the term?
The ist and isms have been overused in both the media and social discourse to the point that they don't really mean anything anymore.